EP0216739A2 - Verfahren und Vorrichtung zum Erhitzen von Glasrohren - Google Patents

Verfahren und Vorrichtung zum Erhitzen von Glasrohren Download PDF

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Publication number
EP0216739A2
EP0216739A2 EP86850318A EP86850318A EP0216739A2 EP 0216739 A2 EP0216739 A2 EP 0216739A2 EP 86850318 A EP86850318 A EP 86850318A EP 86850318 A EP86850318 A EP 86850318A EP 0216739 A2 EP0216739 A2 EP 0216739A2
Authority
EP
European Patent Office
Prior art keywords
mode
tube
cavity
field
microwave
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP86850318A
Other languages
English (en)
French (fr)
Other versions
EP0216739B1 (de
EP0216739A3 (en
Inventor
Yngve Hässler
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Stiftelsen Institutet for Mikrovagsteknik Vid Tekniska Hogskolan
Original Assignee
Stiftelsen Institutet for Mikrovagsteknik Vid Tekniska Hogskolan
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Stiftelsen Institutet for Mikrovagsteknik Vid Tekniska Hogskolan filed Critical Stiftelsen Institutet for Mikrovagsteknik Vid Tekniska Hogskolan
Priority to AT86850318T priority Critical patent/ATE59625T1/de
Publication of EP0216739A2 publication Critical patent/EP0216739A2/de
Publication of EP0216739A3 publication Critical patent/EP0216739A3/en
Application granted granted Critical
Publication of EP0216739B1 publication Critical patent/EP0216739B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B23/00—Re-forming shaped glass
    • C03B23/04—Re-forming tubes or rods
    • C03B23/043—Heating devices specially adapted for re-forming tubes or rods in general, e.g. burners
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
    • C03B37/01—Manufacture of glass fibres or filaments
    • C03B37/012—Manufacture of preforms for drawing fibres or filaments
    • C03B37/014—Manufacture of preforms for drawing fibres or filaments made entirely or partially by chemical means, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD]
    • C03B37/018—Manufacture of preforms for drawing fibres or filaments made entirely or partially by chemical means, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD] by glass deposition on a glass substrate, e.g. by inside-, modified-, plasma-, or plasma modified- chemical vapour deposition [ICVD, MCVD, PCVD, PMCVD], i.e. by thin layer coating on the inside or outside of a glass tube or on a glass rod
    • C03B37/01807—Reactant delivery systems, e.g. reactant deposition burners
    • C03B37/01815—Reactant deposition burners or deposition heating means
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
    • C03B37/01—Manufacture of glass fibres or filaments
    • C03B37/012—Manufacture of preforms for drawing fibres or filaments
    • C03B37/014—Manufacture of preforms for drawing fibres or filaments made entirely or partially by chemical means, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD]
    • C03B37/018—Manufacture of preforms for drawing fibres or filaments made entirely or partially by chemical means, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD] by glass deposition on a glass substrate, e.g. by inside-, modified-, plasma-, or plasma modified- chemical vapour deposition [ICVD, MCVD, PCVD, PMCVD], i.e. by thin layer coating on the inside or outside of a glass tube or on a glass rod
    • C03B37/01876—Means for heating tubes or rods during or immediately prior to deposition, e.g. electric resistance heaters

Definitions

  • This invention relates to a method and an apparatus for heating glass tubes, especially quartz tubes for the manufacture of optical fibres.
  • the method according to the said patent is especially characterized in that the tube is pre-heated to a temperature of about 1000°C-1500°C, preferably by means of a gas flame in a manner known per se, whereafter the tube is heated by means of microwave energy generated by a microwave generator, by introducing the tube axially into a microwave cavity comprising in its two end walls openings for the tube, and the electrical field strength is given a field image including only one tangential component, according to TE-01n-mode, preferably according to the mode TE-011, whereby the electrical field is formed so as to be tangential to the surfaces of the tube, and formed so that the electrical field strength is zero adjacent the surfaces of the cavity.
  • the microwave cavity is of cylindrical configuration and made of metal, and its two end walls includes, as mentioned, openings,through which the tube to be heated is axially introduced.
  • the cavity described in said Swedish patent involves the problem of offering relatively limited possibility of supplying the cavity with such power, that a high temperature of the tube is obtained without thereby causing electrical arcing.
  • This limitation partly is due to the fact that the thermal dissipation from the heated tube is high, and partly because at the passing of the cavity relative to the tube the hot portion of the tube is moved to one end of the cavity, whereby the electrical field is utilized for heating the tube already heated to an extent greater than desired. It is hereby difficult to supply sufficiently high power to the centre of the cavity, i.e. where the tube portion to be heated is located, without giving rise to electric arcing.
  • the cavity is given a relatively high so-called Q-value.
  • the maximum power to be supplied is limited by the necessity of preventing electric arcing, it is desired to be able to reduce the Q-value of the cavity and thereby to be able to supply higher power without causing electric arcing.
  • the said TE-011-mode when used in a cylindric cavity yields a distribution, which is highly advantageous at the heating of quartz tubes to collapsing temperature.
  • the electrical field is zero at the envelope surface of the cavity and in the cavity centre, while the field strength is high in the walls of a thick-walled glass tube.
  • the collapsing is preceded by a deposition phase and a sintering phase.
  • SiO2 On the inner wall of the glass tube layers of pure quartz SiO2 are deposited. In certain layers also germanium dioxide GeO2 is deposited as a doping agent. This is effected in that SiCl4 and oxygen O2, together with GeCl4, are introduced into the tube. SiO2 and GeO2 are herewith deposited on the inner surface of the tube. In order for these reactions to take place, it is necessary to heat the interior of the tube to about 1400°C. This is normally carried out by passing a burner along the entire length of the tube, while rotating the tube about its axis. Firstly, SiCl4 and O2 are introduced, whereupon SiO2 is deposited and forms a porous layer.
  • the layer sinters to form a transparent SiO2.
  • This deposition is repeated, whereafter GeCl4 is mixed with the SiCl4 gas, so as to develop a correct so-called index profile.
  • Normally, 30 to 100 layers are applied during the deposition phase.
  • the temperature of the burner is raised so as to heat the tube to about 2200°C. At this temperature the surface tension causes the tube to draw together, i.e. to collapse.
  • the tube forms a rod, i.e. a so-called preform, from which an optical fibre can be drawn.
  • the present invention meets the requirement of obtaining a high temperature on the inside of the tube wall, and at the same time the method and apparatus according to the invention render it possible to supply a power higher than possible with the TE-011-mode without giving rise to electric arcing.
  • the present invention can advantageously be applied during the deposition and sintering phases, but can also, as explained below, be used during the collapsing phase.
  • the present invention thus, relates to a method of heating glass tubes, particularly quartz tubes for the manufacture of optical fibres, at which method the tube is pre -heated, preferably by means of a gas flame, whereafter the tube is heated by means of microwave energy generated by a microwave generator, by introducing the tube axially into a microwave cavity comprising in its end walls or end surfaces openings for the tube.
  • the invention is characterized in that at least one electrical field is given a field image according to a Tm 0n0-mode, preferably according to the TM 020-mode, which mode has a maxima along the central axis of the cavity and a minima on each side of and radially spaced from the central axis, and that the electrical field portion located between the said minima is utilized for heating the wall of said glass tube.
  • the invention also relates to an apparatus of the kind and having the main characterizing features as defined in claim 4.
  • Fig. 1 shows field lines in an unloaded cylindric cavity by way of a section along the longitudinal axis of the cavity
  • Fig. 2 shows field lines according to Fig. 1 by way of a section across the longitudinal axis thereof
  • Fig. 3 shows field lines in the section shown in Fig. 1 after a load has been introduced into the cavity
  • Fig. 4 shows the amount of the electrical field distribution in radial direction when a load is in the cavity according to two different modes
  • Fig. 5 shows schematically a cavity and its connection to a microwave source.
  • the present invention relates to a method and an apparatus for the manufacture of optical fibres from a glass tube, where the glass tube first is pre-heated, preferably by means of a gas flame, to a temperature of about 1000°C to 1500°C, because the dielectric losses in glass increase substantially from room temperature up to 1000°C-1500°C.
  • the tube is heated by means of microwave energy, which is generated by means of a microwave generator 1, which via a wave-guide 2 is coupled to a microwave cavity 3 of metal.
  • the microwave cavity 3 is provided with openings 4,5 in the end walls 6,7 or end surfaces of the cavity. Through these openings 4,5 the glass tube 8 to be heated is introduced, as shown by dashed lines in Fig. 5. During the heating process the cavity is traversed along the tube in a reciprocatory movement.
  • At least one microwave ge nerator 1 is coupled so via a wave guide 2 to the cavity 6, that an electrical field is given a field image according to a TM-0n0-mode, preferably according to the TM 020-mode, and so that the electrical field has a maxima along the central axis 9 of the cavity 6 and a minima on each side of and radially spaced from the central axis.
  • a cavity further is so utilized that a longitudinal axis through the centre of said openings 4,5 coincides with said central axis 9.
  • the electrical field portion located between said minima is utilized for heating the wall of the glass tube 8.
  • Figs. 1 and 2 are sections along the line A-A in Fig. 1.
  • the electrical field (E-FIELD) is shown by fully drawn lines
  • the magnetic field (H-FIELD) is shown by dashed lines.
  • Crosses indicate field lines running downward in the plane of the paper
  • dots indicate field lines running upward out of the plane of the paper.
  • the field lines of the electrical field as can be seen, run in parallel with the envelope surface of the cavity and terminate at the end walls or end surfaces thereof.
  • Fig. 4 the distribution of the electrical field (E) is shown as a function of the distance X over the cross-section of the cavity along a diameter, see Fig. 2.
  • the said central axis 9 is marked by C-C
  • the glass tube 8 is shown by dash-dotted lines.
  • the field image for the mode TM-020 is marked by fully drawn lines. From Fig. 4 the said maximum 10 and said minima 11,12 appear, which minima are zero positions.
  • the TM-020 mode is characterized by a top located axial-symmetrically in the cavity.
  • n indicates the number of tops located along a radius from the central axis c-c outward to the envelope surface of the cavity.
  • the tops located outside the central top always are lower.
  • the invention therefore, is not restricted to the TM-020-mode. At least the modes TM-010; TM-030 and TM-040 can be used.
  • the TM-020-mode yields a high pocketed electrical field energy in the glass tube 8.
  • the field strength decreases from the inside 13 of the tube to its outside 14 and decreases rapidly outside of the glass tube to said minima 11,12.
  • the cavity By suitably adapting the cavity to the glass tubes to be heated, it is, thus, possible to obtain a substantially higher field strength at the inside of the glass tube than at its outside. This is especially advantageous during the afore-mentioned deposition and, respectively, sintering phase.
  • the inner surface of the glass tube need assume a high temperature, for example 1400-1500°C. Due to the fact that the electrical field is high at the inner surface of the glass tube and lower in the remaining wall parts of the glass tube, the heating is concentrated to the inner surface of the tube. For this reason the power applied to the cavity must not be as high as, for example, when the mode TE-011 is used during the deposition and, respectively. sintering phase.
  • Fig. 4 the field distribution according to the mode TE-011 is shown by dashed lines. It appears from Fig. 4, that the mode TE-011 yields a stronger heating of the outside of the tube than of the inside thereof.
  • the TM-020-mode implies that more electrical field energy is stored in the glass tube and that the field strength decreases to the outer surface of the tube.
  • the greater amount of electrical field energy in its turn implies that a higher load of the cavity is obtained with the TM-020-mode, i.e. that a lower Q-value is obtained. Due to the lower Q-value a higher electrical field strength can be applied without electric arcing occurring for an unchanged value of the loss factor tan ⁇ .
  • the advantage is achieved that the tube must not be pre-heated to a temperature as high as when the TE-011 mode is used.
  • a higher maximum temperature of the tube is achieved by using the TM-020-mode.
  • the TM-020-mode is highly advantageous especially during the deposition and, respectively, sintering phase when primarily the inside of the tube is to be heated.
  • the tube wall must be heated to such an extent that the tube does not crack due to thermal strains.
  • an additional electrical field is caused to be formed in the cavity, which field is given a field image according to a TE-01n-mode, preferably according to the mode TE-011.
  • an additional microwave generator 15 is provided, which via a wave guide 16 is so coupled to the cavity 3, that a TE-01n-mode, preferably the TE-011-mode, appears in the cavity.
  • the TE-011-mode and TM-020-mode or in the more general case the TE-01n-mode and TM-0n0-mode, are suspended upon each other and are independent of each other.
  • both modes are utilized at least during the collapsing phase, where it is advantageous to be able to supply high power and to obtain a uniform temperature over a cross-section of the tube.
  • At least the TM-020-mode is utilized during the deposition phase and sintering phase, and both the TM-020-mode and TE-011-mode are utilized during the collapsing phase.
  • control device 17 of a suitable known kind is provided, which via conductors 18,19 is capable to connect and disconnect the two respective microwave generators 1;15.
  • Fig. 4 the field distribution is shown in a cross-section of a cylindric cavity.
  • the configuration of the cavity can deviate from a cylindric one.
  • a cavity is used which is axial-symmetrical in respect of said central axis 9, which cavity preferably is substantially cylindric.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Geochemistry & Mineralogy (AREA)
  • General Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Manufacturing & Machinery (AREA)
  • Manufacture, Treatment Of Glass Fibers (AREA)
  • Re-Forming, After-Treatment, Cutting And Transporting Of Glass Products (AREA)
  • Glass Melting And Manufacturing (AREA)
  • Glass Compositions (AREA)
  • Steroid Compounds (AREA)
  • Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
  • Optical Fibers, Optical Fiber Cores, And Optical Fiber Bundles (AREA)
  • Constitution Of High-Frequency Heating (AREA)
EP86850318A 1985-09-27 1986-09-19 Verfahren und Vorrichtung zum Erhitzen von Glasrohren Expired - Lifetime EP0216739B1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT86850318T ATE59625T1 (de) 1985-09-27 1986-09-19 Verfahren und vorrichtung zum erhitzen von glasrohren.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE8504498 1985-09-27
SE8504498A SE448297B (sv) 1985-09-27 1985-09-27 Forfarande och anordning for uppvermning av glasror

Publications (3)

Publication Number Publication Date
EP0216739A2 true EP0216739A2 (de) 1987-04-01
EP0216739A3 EP0216739A3 (en) 1988-05-11
EP0216739B1 EP0216739B1 (de) 1991-01-02

Family

ID=20361555

Family Applications (1)

Application Number Title Priority Date Filing Date
EP86850318A Expired - Lifetime EP0216739B1 (de) 1985-09-27 1986-09-19 Verfahren und Vorrichtung zum Erhitzen von Glasrohren

Country Status (9)

Country Link
US (1) US4760230A (de)
EP (1) EP0216739B1 (de)
JP (1) JPS62113732A (de)
AT (1) ATE59625T1 (de)
AU (1) AU589451B2 (de)
DE (1) DE3676405D1 (de)
DK (1) DK461986A (de)
FI (1) FI80558C (de)
SE (1) SE448297B (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0257587A1 (de) * 1986-08-29 1988-03-02 AT&T Corp. Verfahren zum Bekleiden von optischen Vorformen mit Glasruss
EP0261742A1 (de) * 1986-09-26 1988-03-30 Philips Patentverwaltung GmbH Verfahren und Vorrichtung zum Innenbeschichten von Rohren

Families Citing this family (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0173659B1 (de) * 1984-07-03 1989-03-08 Stiftelsen Institutet För Mikrovägsteknik Vid Tekniska Högskolan I Stockholm Verfahren und Vorrichtung zum Erhitzen von dickwandigen Glasrohren
US6121595A (en) * 1997-01-06 2000-09-19 International Business Machines Corporation Applicator to provide uniform electric and magnetic fields over a large area and for continuous processing
US5471037A (en) 1992-08-18 1995-11-28 E. I. Du Pont De Nemours And Company Process for preparing polymeric material with microwave
US6034363A (en) * 1997-02-10 2000-03-07 California Institute Of Technology Uniform batch processing using microwaves
US5958275A (en) * 1997-04-29 1999-09-28 Industrial Microwave Systems, Inc. Method and apparatus for electromagnetic exposure of planar or other materials
US5834744A (en) * 1997-09-08 1998-11-10 The Rubbright Group Tubular microwave applicator
US6104018A (en) * 1999-06-18 2000-08-15 The United States Of America As Represented By The United States Department Of Energy Uniform bulk material processing using multimode microwave radiation
US6259077B1 (en) 1999-07-12 2001-07-10 Industrial Microwave Systems, Inc. Method and apparatus for electromagnetic exposure of planar or other materials
US6246037B1 (en) 1999-08-11 2001-06-12 Industrial Microwave Systems, Inc. Method and apparatus for electromagnetic exposure of planar or other materials
MXPA02005638A (es) 1999-12-07 2002-09-02 Ind Microwave Systems Inc Un reactor cilindrico con una region focal extendida.
EP1361437A1 (de) * 2002-05-07 2003-11-12 Centre National De La Recherche Scientifique (Cnrs) Ein neuer biologischer Tumormarker und Methoden für die Detektion des krebsartigen oder nicht krebsartigen Phenotyps von Zellen
US6870124B2 (en) 2002-05-08 2005-03-22 Dana Corporation Plasma-assisted joining
US7497922B2 (en) 2002-05-08 2009-03-03 Btu International, Inc. Plasma-assisted gas production
US7465362B2 (en) 2002-05-08 2008-12-16 Btu International, Inc. Plasma-assisted nitrogen surface-treatment
US7494904B2 (en) 2002-05-08 2009-02-24 Btu International, Inc. Plasma-assisted doping
US7560657B2 (en) 2002-05-08 2009-07-14 Btu International Inc. Plasma-assisted processing in a manufacturing line
US7445817B2 (en) 2002-05-08 2008-11-04 Btu International Inc. Plasma-assisted formation of carbon structures
US7498066B2 (en) * 2002-05-08 2009-03-03 Btu International Inc. Plasma-assisted enhanced coating
US7638727B2 (en) 2002-05-08 2009-12-29 Btu International Inc. Plasma-assisted heat treatment
US7432470B2 (en) 2002-05-08 2008-10-07 Btu International, Inc. Surface cleaning and sterilization
US7189940B2 (en) 2002-12-04 2007-03-13 Btu International Inc. Plasma-assisted melting

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2249847A1 (en) * 1973-11-06 1975-05-30 Thomson Csf Glass fibre pulling system - in which glass rod end is heated in resonance cavity of UHF waveguide
FR2288958A1 (fr) * 1974-10-21 1976-05-21 Desmarquest & Cec Installation pour le traitement par zone de produits de forme allongee
US4090055A (en) * 1977-02-10 1978-05-16 Northern Telecom Limited Apparatus for manufacturing an optical fibre with plasma activated deposition in a tube
US4292063A (en) * 1980-05-05 1981-09-29 Northern Telecom Limited Manufacture of an optical fiber preform with micro-wave plasma activated deposition in a tube
FR2505472A1 (fr) * 1981-05-05 1982-11-12 Lignes Telegraph Telephon Dispositif de concentration d'energie infrarouge et dispositif de fabrication de fibres optiques comportant un tel dispositif de concentration
EP0173659A2 (de) * 1984-07-03 1986-03-05 Stiftelsen Institutet För Mikrovägsteknik Vid Tekniska Högskolan I Stockholm Verfahren und Vorrichtung zum Erhitzen von dickwandigen Glasrohren

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3465114A (en) * 1966-09-19 1969-09-02 Canadian Patents Dev Method and apparatus for dielectric heating
US3461261A (en) * 1966-10-31 1969-08-12 Du Pont Heating apparatus
US4144434A (en) * 1976-06-14 1979-03-13 Societe Lignes Telegraphiques Et Telephoniques Microwave heating devices
SE411162B (sv) * 1978-02-03 1979-12-10 Husqvarna Ab Forfaringssett vid framstellning av livsmedel, innehallande koagulerade eggviteemnen, och en anordning for settets utforande
NL8402999A (nl) * 1984-10-02 1986-05-01 Philips Nv Mikrogolfinrichting voor het verhitten van materiaal.

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2249847A1 (en) * 1973-11-06 1975-05-30 Thomson Csf Glass fibre pulling system - in which glass rod end is heated in resonance cavity of UHF waveguide
FR2288958A1 (fr) * 1974-10-21 1976-05-21 Desmarquest & Cec Installation pour le traitement par zone de produits de forme allongee
US4090055A (en) * 1977-02-10 1978-05-16 Northern Telecom Limited Apparatus for manufacturing an optical fibre with plasma activated deposition in a tube
US4292063A (en) * 1980-05-05 1981-09-29 Northern Telecom Limited Manufacture of an optical fiber preform with micro-wave plasma activated deposition in a tube
FR2505472A1 (fr) * 1981-05-05 1982-11-12 Lignes Telegraph Telephon Dispositif de concentration d'energie infrarouge et dispositif de fabrication de fibres optiques comportant un tel dispositif de concentration
EP0173659A2 (de) * 1984-07-03 1986-03-05 Stiftelsen Institutet För Mikrovägsteknik Vid Tekniska Högskolan I Stockholm Verfahren und Vorrichtung zum Erhitzen von dickwandigen Glasrohren

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0257587A1 (de) * 1986-08-29 1988-03-02 AT&T Corp. Verfahren zum Bekleiden von optischen Vorformen mit Glasruss
US4941905A (en) * 1986-08-29 1990-07-17 American Telephone And Telegraph Company, At&T Technologies, Inc. Methods of soot overcladding an optical preform
EP0261742A1 (de) * 1986-09-26 1988-03-30 Philips Patentverwaltung GmbH Verfahren und Vorrichtung zum Innenbeschichten von Rohren
US4877938A (en) * 1986-09-26 1989-10-31 U.S. Philips Corporation Plasma activated deposition of an insulating material on the interior of a tube

Also Published As

Publication number Publication date
JPH0469571B2 (de) 1992-11-06
JPS62113732A (ja) 1987-05-25
FI80558C (fi) 1990-06-11
DE3676405D1 (de) 1991-02-07
DK461986D0 (da) 1986-09-26
SE8504498D0 (sv) 1985-09-27
SE448297B (sv) 1987-02-09
DK461986A (da) 1987-03-28
FI863898A0 (fi) 1986-09-26
ATE59625T1 (de) 1991-01-15
AU6304986A (en) 1987-04-02
FI863898A (fi) 1987-03-28
US4760230A (en) 1988-07-26
EP0216739B1 (de) 1991-01-02
AU589451B2 (en) 1989-10-12
FI80558B (fi) 1990-02-28
EP0216739A3 (en) 1988-05-11

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